Impact of Chemomechanical Polishing on the Chemical Composition and Morphology of the Silicon Surface

1995 ◽  
Vol 386 ◽  
Author(s):  
Hermann Fusstetrer ◽  
Anton Schnegg ◽  
Dieter Gräf ◽  
Helmut Kirschner ◽  
Michael Brohl ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Silicon Surface ◽  
Large Scale ◽  
Nucleophilic Attack ◽  
Force Microscopy ◽  
Atomic Force ◽  
Light Point ◽  
Resolution Electron ◽  
Surface Irregularities ◽  
Electron Energy Loss

ABSTRACTThe polishing technology used for manufacturing ultraflat and smooth Si surfaces on a large scale is the chemomechanical polishing (CMP) technique. This technique combines the chemical corrosive removal of silicon atoms and the mechanical transport of the agents. The removal rates strongly depend on the interaction of mechanical parameters and the chemistry involved in the polishing process like the pH of the alkaline polishing slurry used. Removal of Si during CMP is explained by a nucleophilic attack of OH− to silicon atoms catalyzing the corrosive reaction of H2O resulting in cleavage of silicon backbonds. Characterization of the surface chemistry of the silicon wafer after polishing by X-Ray Photoelectron Spectroscopy and High-Resolution Electron Energy Loss Spectroscopy reveals an oxide free, predominantly hydride covered silicon surface displaying hydrophobic properties. Morphological features like microroughness as well as localized surface irregularities on the silicon surface, also referred to as Light Point Defects, depend on different strongly interacting process parameters. Microroughness is reduced by CMP by several orders of magnitude as characterized by lightscattering techniques and Atomic Force Microscopy.

Chemical and Structural Analysis of Nitridated Sapphire

1997 ◽  
Vol 482 ◽  
Author(s):  
Y. Cho ◽  
S. Rouvimov ◽  
Y. Kim ◽  
Z. Liliental-Weber ◽  
E. R. Weber
Keyword(s):  
Electron Microscopy ◽  
Atomic Force Microscopy ◽  
Structural Analysis ◽  
Photoelectron Spectroscopy ◽  
High Resolution Electron Microscopy ◽  
Cross Sectional ◽  
Force Microscopy ◽  
Sapphire Substrates ◽  
Atomic Force ◽  
Resolution Electron

AbstractThe incorporation of nitrogen into sapphire substrates during nitridation was studied by xray photoelectron spectroscopy (XPS). An increase in the intensity of nitrogen 1s peak in XPS was observed upon longer nitridation. The surface morphology of the substrates was characterized by atomic force microscopy (AFM). High resolution electron microscopy (HREM) was employed for structural analysis. The cross sectional TEM showed a thin layer of AlN buried between amorphous AlNxO1−x and sapphire. This is the first direct observation of AlN on sapphire. The TEM images show a deeper penetration depth of nitrogen into a longer nitridated sapphire.

scholarly journals Investigation on energy bandgap states of amorphous SiZnSnO thin films

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Byeong Hyeon Lee ◽  
Kyung-Sang Cho ◽  
Doo-Yong Lee ◽  
Ahrum Sohn ◽  
Ji Ye Lee ◽  
...  
Keyword(s):  
Fermi Level ◽  
Photoelectron Spectroscopy ◽  
Systematic Change ◽  
Kelvin Probe ◽  
Force Microscopy ◽  
Energy Bandgap ◽  
Resolution Electron ◽  
The Difference ◽  
Electron Energy Loss ◽  
Good Agreement

AbstractThe variation in energy bandgaps of amorphous oxide semiconducting SiZnSnO (a-SZTO) has been investigated by controlling the oxygen partial pressure (Op). The systematic change in Op during deposition has been used to control the electrical characteristics and energy bandgap of a-SZTO. As Op increased, the electrical properties degraded, while the energy bandgap increased systematically. This is mainly due to the change in the oxygen vacancy inside the a-SZTO thin film by controlling Op. Changes in oxygen vacancies have been observed by using X-ray photoelectron spectroscopy (XPS) and investigated by analyzing the variation in density of states (DOS) inside the energy bandgaps. In addition, energy bandgap parameters, such as valence band level, Fermi level, and energy bandgap, were extracted by using ultraviolet photoelectron spectroscopy, Kelvin probe force microscopy, and high-resolution electron energy loss spectroscopy. As a result, it was confirmed that the difference between the conduction band minimum and the Fermi level in the energy bandgap increased systematically as Op increases. This shows good agreement with the measured results of XPS and DOS analyses.

Patterning biopolymer surfaces by enzymatic soft lithography

2011 ◽  
Vol 1340 ◽  
Author(s):  
A. Guyomard-Lack ◽  
C. Moreau ◽  
N. Delorme ◽  
J.-F. Bardeau ◽  
B. Cathala
Keyword(s):  
Soft Lithography ◽  
Silicon Surface ◽  
Large Scale ◽  
Microcontact Printing ◽  
Lateral Diffusion ◽  
Patterned Surfaces ◽  
Force Microscopy ◽  
Atomic Force ◽  
Ink Transfer ◽  
Micro Patterns

ABSTRACTA novel rapid and easy-to-use method for patterning surfaces on large scale is described. Micro-patterns were created by direct contact of trypsin-functionalized poly(dimethylsiloxane) (PDMS) stamps with poly-L-lysine (PLL) layer adsorbed on silicon surface. The catalytic process does not involve ink transfer and thus lateral diffusion is avoided. As a result duplication of the stamp pattern is highly enhanced comparatively to standard microcontact printing procedure where PLL is used as ink and transferred on silicon surface. Patterning was revealed by fluorescence microscopy and atomic force microscopy (AFM). Adsorption on the patterned surfaces of cellulose nanocrystals was investigated as an example of application.

Characterizing Chiral Molecules Deposited onto a Silicon Surface

2017 ◽  
Author(s):  
Stephen Gauthier
Keyword(s):  
Photoelectron Spectroscopy ◽  
Silicon Surface ◽  
Mirror Image ◽  
Chiral Molecules ◽  
Chiral Chromatography ◽  
Force Microscopy ◽  
Drug Molecules ◽  
Atomic Force ◽  
Derivatives Of

We report here on the characterization of two types of chiral molecules deposited onto a silicon surface. Chiral molecules are non­superimposable mirror images of each other. Other than the way they interact with biological systems, chiral molecules have the same physical properties which make them hard to  separate. Since many important drug molecules are chiral, effective separation methods are required by  industry. We are building a model system to study one separation method called chiral chromatography. In chiral chromatography, separation is achieved by immobilizing a chiral compound along a column and  passing the desired chiral mixture through. One of the mirror image molecules of the mixture has a higher  attraction to the immobilized phase which causes it to exit the column at a later time. In the model being  studied, propranolol is the sample drug molecule and phenylethylpropylurea (PEPU) is the selector  molecule. Derivatives of these compounds were deposited onto a flat silicon surface. The resulting  samples were studied in order to gain insight into the surface morphology and characteristics of the assembled layers. Using a combination of infra red (IR) spectroscopy and computational analysis it was possible to infer the average bulk molecular orientation of the deposited propranolol molecules. Atomic force microscopy was used to ensure a uniform deposition as well as to quantify the surface roughness. Through X­ray photoelectron spectroscopy (XPS) analysis it was shown that an average layer thickness of  four molecules was deposited onto the silicon

Polyelectrolyte-Induced Dispersion of Graphene Sheets in the Hybrid AgCl/PDDA/Graphene Nanocomposites

2013 ◽  
Vol 663 ◽  
pp. 357-360
Author(s):  
Yan Qing Wang ◽  
Ling Sun ◽  
Bunshi Fugetsu
Keyword(s):  
Photoelectron Spectroscopy ◽  
Self Assembly ◽  
Large Scale ◽  
Cationic Polyelectrolyte ◽  
Graphene Sheets ◽  
Graphene Nanocomposites ◽  
Force Microscopy ◽  
Atomic Force ◽  
Diallyldimethylammonium Chloride ◽  
Environmentally Friendly Approach

Cationic polyelectrolyte poly(diallyldimethylammonium chloride) (PDDA) was used to stabilize graphene sheets in the self-assembly of AgCl/PDDA/Graphene heterostructure. The resultant AgCl/PDDA/Graphene nanocomposites were characterized by Scanning electron microscopy, Atomic force microscopy and X-ray photoelectron spectroscopy. The results showed that AgCl nanoparticles with sizes of 500 nm uniformly positioned on the PDDA stabilized graphene sheets surface. This work presents a facile and environmentally friendly approach to the synthesis of AgCl/PDDA/Graphene and opens up a new possibility for preparing graphene-based nanomaterials for large-scale applications.

scholarly journals Fast and Straightforward Synthesis of Luminescent Titanium(IV) Dioxide Quantum Dots

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Václav Štengl ◽  
Jiří Henych ◽  
Martin Šťastný ◽  
Martin Kormunda
Keyword(s):  
Quantum Dots ◽  
Photoelectron Spectroscopy ◽  
High Resolution Electron Microscopy ◽  
Fast Method ◽  
X Ray ◽  
Force Microscopy ◽  
Selected Area Electron Diffraction ◽  
Atomic Force ◽  
Resolution Electron ◽  
Close Range

The nucleus of titania was prepared by reaction of solution titanium oxosulphate with hydrazine hydrate. These titania nuclei were used for titania quantum dots synthesis by a simple and fast method. The prepared titanium(IV) dioxide quantum dots were characterized by measurement of X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), high-resolution electron microscopy (HRTEM), and selected area electron diffraction (SAED). The optical properties were determined by photoluminescence (PL) spectra. The prepared titanium(IV) dioxide quantum dots have the narrow range of UV excitation (365–400 nm) and also a close range of emission maxima (450–500 nm).

Investigation of the Effect of Uv-Assisted Oxidation and Nitridation of Hafnium Metal Films

2003 ◽  
Vol 780 ◽  
Author(s):  
C. Essary ◽  
V. Craciun ◽  
J. M. Howard ◽  
R. K. Singh
Keyword(s):  
Uv Radiation ◽  
Photoelectron Spectroscopy ◽  
Grazing Angle ◽  
X Ray Diffraction ◽  
Metal Thin Films ◽  
X Ray ◽  
Force Microscopy ◽  
Si Substrates ◽  
Atomic Force ◽  
Silicon Interface

AbstractHf metal thin films were deposited on Si substrates using a pulsed laser deposition technique in vacuum and in ammonia ambients. The films were then oxidized at 400 °C in 300 Torr of O2. Half the samples were oxidized in the presence of ultraviolet (UV) radiation from a Hg lamp array. X-ray photoelectron spectroscopy, atomic force microscopy, and grazing angle X-ray diffraction were used to compare the crystallinity, roughness, and composition of the films. It has been found that UV radiation causes roughening of the films and also promotes crystallization at lower temperatures.Furthermore, increased silicon oxidation at the interface was noted with the UVirradiated samples and was shown to be in the form of a mixed layer using angle-resolved X-ray photoelectron spectroscopy. Incorporation of nitrogen into the film reduces the oxidation of the silicon interface.

scholarly journals Photocatalytic reduction of graphene oxide with cuprous oxide film under UV-vis irradiation

2020 ◽  
Vol 59 (1) ◽  
pp. 207-214 ◽  
Author(s):  
Yao Wang ◽  
Jianqing Feng ◽  
Lihua Jin ◽  
Chengshan Li
Keyword(s):  
Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Low Cost ◽  
Photocatalytic Reduction ◽  
Force Microscopy ◽  
Atomic Force ◽  
Reduced Graphene ◽  
Reduction Efficiency ◽  
Metal Organic ◽  
Reduction Effect

AbstractWe have grown Cu2O films by different routes including self-oxidation and metal-organic deposition (MOD). The reduction efficiency of Cu2O films on graphene oxide (GO) synthesized by modified Hummer’s method has been studied. Surface morphology and chemical state of as-prepared Cu2O film and GO sheets reduced at different conditions have also been investigated using atomic force microscopy (AFM) and x-ray photoelectron spectroscopy (XPS). Results show that self-oxidation Cu2O film is more effective on phtocatalytic reduction of GO than MOD-Cu2O film. Moreover, reduction effect of self-oxidation Cu2O film to GO is comparable to that of environmental-friendly reducing agent of vitamin C. The present results offer a potentially eco-friendly and low-cost approach for the manufacture of reduced graphene oxide (RGO) by photocatalytic reduction.

scholarly journals Interface Structures and Electronic States of Epitaxial Tetraazanaphthacene on Single-Crystal Pentacene

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1088
Author(s):  
Yuki Gunjo ◽  
Hajime Kamebuchi ◽  
Ryohei Tsuruta ◽  
Masaki Iwashita ◽  
Kana Takahashi ◽  
...  
Keyword(s):  
Single Crystal ◽  
Photoelectron Spectroscopy ◽  
Grazing Incidence ◽  
Force Microscopy ◽  
Interface Dipole ◽  
Atomic Force ◽  
Interfacial Structures ◽  
Donor And Acceptor ◽  
A Charge ◽  
Interface Structures

The structural and electronic properties of interfaces composed of donor and acceptor molecules play important roles in the development of organic opto-electronic devices. Epitaxial growth of organic semiconductor molecules offers a possibility to control the interfacial structures and to explore precise properties at the intermolecular contacts. 5,6,11,12-tetraazanaphthacene (TANC) is an acceptor molecule with a molecular structure similar to that of pentacene, a representative donor material, and thus, good compatibility with pentacene is expected. In this study, the physicochemical properties of the molecular interface between TANC and pentacene single crystal (PnSC) substrates were analyzed by atomic force microscopy, grazing-incidence X-ray diffraction (GIXD), and photoelectron spectroscopy. GIXD revealed that TANC molecules assemble into epitaxial overlayers of the (010) oriented crystallites by aligning an axis where the side edges of the molecules face each other along the [1¯10] direction of the PnSC. No apparent interface dipole was found, and the energy level offset between the highest occupied molecular orbitals of TANC and the PnSC was determined to be 1.75 eV, which led to a charge transfer gap width of 0.7 eV at the interface.

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